Cam to IoXT as fast as IoXT to Comp via Thunderbolt?

[Frank Black]

I think I get it: the capture card captures the camera’s playback, and the playback is the uncompressed/decoded version. SDI passes in real-time. Now here’s a question — if the camera is playing back in real-time, and there’s an hour of footage, how is it that I’ve seen videos on Youtube where over thunderbolt, data was transferred in a flash almost. How can thunderbolt transfer faster than the capture card is capturing, considering that it is capturing in real-time — meaning 1 hour (since it takes one hour to play back an hour of footage in real-time)? Thanks.

[Rob Hargreaves]

How does the IO XT assist in editing?
Is it just to allow output to a broadcast monitor or is there some other benefits?
I already have a second monitor connected to my MBP 17″ via the TB/Mini Displayport works work fine in PPro CS 5.5 or FCPX 10.0.0.3, so what advantage is gain on the “editing” side?

Also I don’t see any information about stream HD from the IO XT, is this possible?
Thanks